diff options
Diffstat (limited to 'block/blk-softirq.c')
-rw-r--r-- | block/blk-softirq.c | 156 |
1 files changed, 0 insertions, 156 deletions
diff --git a/block/blk-softirq.c b/block/blk-softirq.c deleted file mode 100644 index 6e7ec87d49fa..000000000000 --- a/block/blk-softirq.c +++ /dev/null @@ -1,156 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0 -/* - * Functions related to softirq rq completions - */ -#include <linux/kernel.h> -#include <linux/module.h> -#include <linux/init.h> -#include <linux/bio.h> -#include <linux/blkdev.h> -#include <linux/interrupt.h> -#include <linux/cpu.h> -#include <linux/sched.h> -#include <linux/sched/topology.h> - -#include "blk.h" - -static DEFINE_PER_CPU(struct list_head, blk_cpu_done); - -/* - * Softirq action handler - move entries to local list and loop over them - * while passing them to the queue registered handler. - */ -static __latent_entropy void blk_done_softirq(struct softirq_action *h) -{ - struct list_head *cpu_list, local_list; - - local_irq_disable(); - cpu_list = this_cpu_ptr(&blk_cpu_done); - list_replace_init(cpu_list, &local_list); - local_irq_enable(); - - while (!list_empty(&local_list)) { - struct request *rq; - - rq = list_entry(local_list.next, struct request, ipi_list); - list_del_init(&rq->ipi_list); - rq->q->mq_ops->complete(rq); - } -} - -#ifdef CONFIG_SMP -static void trigger_softirq(void *data) -{ - struct request *rq = data; - struct list_head *list; - - list = this_cpu_ptr(&blk_cpu_done); - list_add_tail(&rq->ipi_list, list); - - if (list->next == &rq->ipi_list) - raise_softirq_irqoff(BLOCK_SOFTIRQ); -} - -/* - * Setup and invoke a run of 'trigger_softirq' on the given cpu. - */ -static int raise_blk_irq(int cpu, struct request *rq) -{ - if (cpu_online(cpu)) { - call_single_data_t *data = &rq->csd; - - data->func = trigger_softirq; - data->info = rq; - data->flags = 0; - - smp_call_function_single_async(cpu, data); - return 0; - } - - return 1; -} -#else /* CONFIG_SMP */ -static int raise_blk_irq(int cpu, struct request *rq) -{ - return 1; -} -#endif - -static int blk_softirq_cpu_dead(unsigned int cpu) -{ - /* - * If a CPU goes away, splice its entries to the current CPU - * and trigger a run of the softirq - */ - local_irq_disable(); - list_splice_init(&per_cpu(blk_cpu_done, cpu), - this_cpu_ptr(&blk_cpu_done)); - raise_softirq_irqoff(BLOCK_SOFTIRQ); - local_irq_enable(); - - return 0; -} - -void __blk_complete_request(struct request *req) -{ - struct request_queue *q = req->q; - int cpu, ccpu = req->mq_ctx->cpu; - unsigned long flags; - bool shared = false; - - BUG_ON(!q->mq_ops->complete); - - local_irq_save(flags); - cpu = smp_processor_id(); - - /* - * Select completion CPU - */ - if (test_bit(QUEUE_FLAG_SAME_COMP, &q->queue_flags) && ccpu != -1) { - if (!test_bit(QUEUE_FLAG_SAME_FORCE, &q->queue_flags)) - shared = cpus_share_cache(cpu, ccpu); - } else - ccpu = cpu; - - /* - * If current CPU and requested CPU share a cache, run the softirq on - * the current CPU. One might concern this is just like - * QUEUE_FLAG_SAME_FORCE, but actually not. blk_complete_request() is - * running in interrupt handler, and currently I/O controller doesn't - * support multiple interrupts, so current CPU is unique actually. This - * avoids IPI sending from current CPU to the first CPU of a group. - */ - if (ccpu == cpu || shared) { - struct list_head *list; -do_local: - list = this_cpu_ptr(&blk_cpu_done); - list_add_tail(&req->ipi_list, list); - - /* - * if the list only contains our just added request, - * signal a raise of the softirq. If there are already - * entries there, someone already raised the irq but it - * hasn't run yet. - */ - if (list->next == &req->ipi_list) - raise_softirq_irqoff(BLOCK_SOFTIRQ); - } else if (raise_blk_irq(ccpu, req)) - goto do_local; - - local_irq_restore(flags); -} - -static __init int blk_softirq_init(void) -{ - int i; - - for_each_possible_cpu(i) - INIT_LIST_HEAD(&per_cpu(blk_cpu_done, i)); - - open_softirq(BLOCK_SOFTIRQ, blk_done_softirq); - cpuhp_setup_state_nocalls(CPUHP_BLOCK_SOFTIRQ_DEAD, - "block/softirq:dead", NULL, - blk_softirq_cpu_dead); - return 0; -} -subsys_initcall(blk_softirq_init); |